Process and apparatus for the electric firing of materials and ores.



W. H. HAMPTON.

PROCESS ANDAPPARATUS FOR THE ELECTRIC FIRING OF MATERIALS AND ORES. APPLICATION FILED mu 3, 1913.

1, 171 1 17. Patented Feb. 8,1916.

2 SHEEN-SHEET I W. H. HAMPTON.

' PROCESS AND APPARATUS FOR THE ELECTRIC FIRING OF MATERIALS AND ORES.

' APPLICATION FILED MAY 3, I9I3- 1,17L1 17. Patented Feb. 8,1916.

2 SHEETS-SHEET 2.

WOPIZM UNITED STATES PATENT OFFICE.

WILLIAM H. HAMPTON, OF NEW YORK, N. Y., ASSIGNOR TO THE CONLEY ELECTRIC FURNACE COMPANY, INCORPORATED, OF WILMINGTON, DELAWARE, A CORPORA- TION OF DELAWARE.

PROCESS AND APPARATUS FOR THE ELECTRIC FIRING OF MATERIALS AND ORES.

To all whom it may concern:

Be it known that I, WILLIAM H. HAMP- TON, a citizen of the United States, residing at New York, in the county and State of New York, have invented Improvements in Processes and Apparatus for the Electric Firing of Materials and Ores,=of which thefollowing is a specification. '-Th1s invention comprises a process and apparatus for the electric firing of materials process and apparatus for the treatment of ore, wherein successive or continuous portions of the materlal are caused to progress across or at right anglesto a heated blast,

so as to be brought to, into and beyond the intensely heated region.

The apparatus is desirably embodied in an endless or circular conveyer or grate, or a series of perforated carriers which travel in acircuit, in conjunction with means for causing air or other oxidizing or even inert gas to pass into or through and beyond the ore in a general direction transverse to the travel, and an arrangement of non-metallic and non-arcing resistance conductors or incandescing elements, a number of which are in close proximity to the ore, for heating the air or other gas before passing into the ore.

An advantageous feature of the invention is the provision of separate blasts or meansfor dividing the fluid that passes through the ore, so that the portion which is rich in products of combustion or volatilization and suitable for utilization is keptseparate from the portion which is poor in such products, or which consists mainly or entirely of a draft current for cooling the roasted, sintered or calcined product of the heated blast.

In another respect, therefore, the invention includes the firing of a traveling ore Specification of Letters Patent.

charge or layer at one point in its travel by an electrically heatedblast, and the cooling of the fired product at a subsequent pointbv means of a cool blast. t

From the foregoing it will be apparent that the invention possesses numerous advantages.

Among its objects are to enable ore deficlent in combustible content to be blastroas ted, sintered or calcined, rapidly and effic ently, or to increase the rapidity and efliciency of roasting and sintering operat1ons 1n the cases of ores which are of such character as to generate a considerable amount of heat by internal combustion.

In the accompanying drawings which show an illustrative embodiment of the invention: Figure l is a fragmentary side sectional elevation of the preferred form of the apparatus; Fig. 2 is a cross-section taken on the line 22 of Fig. 1, and including a diagrammatic illustration of electric circuits; and Fig. 3 is a perspective view of a holder block for supporting the electric laeating elements.

As those familiar with the art of blast roasting and sintering are aware, various forms of ore carrier or conveyer may be utilized, such as rotary upright wheels, rotary horizontal disks, endless conveyers traveling over spacedsupports, or separate containers traveling one after another in a circuit. Also the blast may be created either by forcing or by suction. The same range of variation'applies to the present invention.

In the accompanying drawings the preferred form of carrier is illustrated, the same consisting of an endless chain conveyer 10,

Patented Feb. 8, 1916. Application filed May 3, 1913. Serial No. 765,380.

composed of boxor trough-like sections 11,

hinged together as at 12 and provided with perforated bottoms '13. At opposite ends of the course the conveyer or the lateral portions thereof travel over sprocket wheels, one of which is shown at 14.

The ore is fed or charged onto or into the conveyer or the sections thereof adjacent one end of the course and is thence transported along a stralght or curved path to a-point of discharge, not shown in the drawings but all as well understood in the art. The charging may be by gravity from a bin or hopper, or in any other suitable way. A single kind or grade of ore may be fed to the conveyer, or ore of two different kinds or from separate bodies may be fed to the conveyer, and Stratified if desired. 5 The possibilities in this regard are conventionally represented by two ho pers 15, 16, one in front of the other'an adapted to lay superposed strata on the conveyer bot-' tom.

Between the point of feeding and the point of discharge a heated blast is caused to act transversely of the path of the traveling ore and topass into and preferably through and beyond the same. In the pres- .ent instance the blast is shown as being created by suction. To this end an air box 17' is disposed at one side of the traveling carrier, preferably below it, the construction being such that the box makes a sub- 20 stantially air tight joint with the conveyer or the sections thereof. This box extends for a suitable distance lengthwise of the run,-and the flow through theconveyer into the box and thence to-a suitable point of discharge or utilization is produced by an exhaust fan 18 connected with the box by a Y of combustible material the portion of the pipe 19.

The heating of the blast that passes into the interior of the ore body is effected by an electric resistance heater, the best embodiment of which comprises a plurality of non-metallic high resistance conductors in the nature of bars 20 molded of a composition of clay and graphite, of which the most desirable proportions are approximately sixty per cent. of clay to forty per cent. of carbon. These bars may be arranged in various ways, for example cross-wise, over the .c'onveyer, and there may be one or more tiers 40 of them as conditions may require. Two sets are shown, one above the other, the lower tier in close proximity to the running ore so as to subject'it to an intense heat. These, heating or incandescing bars are mounted in blocks or tiles 21, of suitable heat resisting and electric non-conducting material. As shown in Figs. 1 and 3, these blocks are preferably constructed and arranged so as to form one or more chambers 2'2, 23, which are traversed by the heating elements. Air or other fluid is admitted to these chambers through perforations 24 in the tops and depending end portions 25 of the said blocks. The blocks are formed in 5 their adjoining sides with registering recesses or grooves, which complement each other to form sockets for the reception of the heating bars, which may be of dove-tail formation as shown. In the construction illustrated, the depending end portions 25 of the blocks .form two sides of the air cham-' bers, and blocks 26, 27 on which the topsof the blocks 21rest, form the other sides of. the chambers. The lower blocks 27 are mount'ed on suitable supports, indicated at 28 in Fig. 2. The air which passes through the openings 24; cools the holder blocks 21 and thereby takes up a certain amount of heat, and is raised to a high temperature in the chambers 22, 23 by radiation from the incandescent elements 20. The means for supplying theseresistance conductors with current, soas to cause them to become in candescent, is indicated diagrammatically in Fig. 2, wherein 29 represents a transformer across-the mains of which the resistance conductors are connected in parallel or multiple. As indicated, variable resistances or inductances 30 may be provided for relatively varying the current flowing to different resistance conductors and thus relatively varying the degree of heat prodiIced thereby. Thus, the lower tier of bars 20 may be heated more intensely than the upper tier or-vice-versa, or the heating eles5 ments in the order in which they are passed by the traveling ore may be heated to different degrees'of intensity. Thus, the material as it travels may be subjected to successively higher temperatures or the reverse. For example, if the ore contains a certain amount air blast first encountered may be heated to a higher degree than the portions of the blast farther along the travel so that the 5' more intense initial heat ignites the material, after which the highly heated portions of the blast supply sufficient heat to maintain the combustion in the body of the ore.

. It will be observed that'my invention does 9 away with the use of any fuel burning igniter for sintering and blast-roasting processes, and,'in fact, it is within the scope of my invention 'to utilizemy electric firing 'means inerely to initially ignite the ore, the

necessary heat thereafter being supplied solely by internal combustion. In the case of ore having suflicient combustible content to maintain the desired action by the heat of internal combustion my electric firing means may be used with advantage both to ignite the material and to heat the blast which thereafter supports combustion, so that the action in the body oftthe ore is rendered more rapid. For such purpose, as already indicated, all portions' f the blast may be heated to the same degree, or the part thereof first encountered by the ore in its movement maybe heated more intensely so as to i start the combustion. I When the air passes beyond the range of the blast heated by the resistance elements 20 the operation, if it be merely one of cal cining, is completed, and thereafter the fired product may be dumped, though my present invention contemplates first cooling it by 'a coolblast or cool portion of the blast, which may be caused to .pass' through the conveyer and material in the" same manner as the heated blast. If the operation is a roasting or sintering, the rate of travel, the degree of heat, and the length of the portion of the path of the ore over which the heating means extends, may be such that the action is complete by the time that the ore passes beyond the electric heater, or it may be practically or partially completed, the remainder of the action being performed under a relatively cooler or unheated blast; and the same blast, or a blast subsequently encountered, serves to cool the fired product or sinter before it is discharged, so that it may be conveniently handled. It will be apparent that separate draft forcing or inducing means may be used for the several blasts, in which event the pressures andv velocities of the difi'erent blasts can be rela-.

tively varied, or that a single fan or the like blasts ora common blast, which is divided by draft-controlling means or differentiated by means for causing different portions of the blasts to have different temperatures. It will be obvious that with a single draft forcing or inducing means it is possible to relatively vary the pressures and velocities of the successive blasts created thereby by i t1on is that the preheated air rapidly 0x1- manipulation of suitable draft-controlling devices, such as are customarily used for regulating the pressure or flow of gases.

In the accompanying drawings separate air boxes 17 and 31 are shown arranged one after the other in the direction of travel.

.The box 17 is of approximately the same ex'- connected with it bya pipe 33. The provision of separate boxes or conduits having separate outlets, as indicated, is of advantage in that it enables the blast passing from the ore to be divided into a portion rich enough in products of combustion to be available for utilization and a portion poorer in such products or consisting solely of a cooling draft, which may be allowed to escape.

In operation the ore or ore mixture is fed in any suitable manner, such, for example, as indicated, in one or more layers upon the traveling carrier or conveyer. In general, best results are secured when the body or bodies of ore thus set in motion are relatively thin transverse to the direction of travel, that is to say, thin in the direction of movement of the air blast. If the operation is a sintering one, care is taken that all the particles ,of the ore remain-in quiescence until the operation is complete. As is well understood in the art, the provision of a carrier having aperforated bottom together with a down-draft, so that the perforated bottom cg screen prevents agitation of the material l at the side where the blast emerges, is effective for accomplishing this end. When,

however, the operation is not a sintering one,

the material may be agitated if desired. It will be understood that a down-draft is not essential in all instances. The material is fired by intercepting a heated blast, and with the means contemplated in my invention the .not only to ignite the material, but to there:

after maintain the action. In case the ore contains sufficient combustible material to burn of, itself the action may be forced by preheating the blast in the manner provided by this invention. After the roasting, sintering,'calcining or other action has progressed completely through the body or successive bodies of ore, the product is continuously cooled by the cool blast and discharged.

One of the great. advantages of my invening removed much more quickly and expeditiously than in cases where a cold blast is used. Furthermore, in roasting and sinte'ring operations'the heat ofcombustion is not wasted in part by having to heat up cold incoming-air. Therefore, ores' with less sulfur content can be successfully roasted and sintered and in cases Where fuel is added a less amount is sufficient.

Having thus described my invention, what I claim as new is:

1. An apparatus for the treatment of ore, comprising a. movable carrier for the ore,

means for causing a blast to pass into the ore charge at a point in its travel, and electrical means for heating the blast.

2. An apparatus for the treatment of ore, comprising meansfor creating and controlling a continuous blast, electric resistance heating means for heating the fluid forming said blast, and means for transporting successive or continuous portions ofv the 'ore charge across such heated blast.

3. In an apparatus .of the character described, the combination of a carrier for the ore, electric heating means at one side of the path of the ore transported by said carrier, I

and means for causing air to flow over said electric heating means-into the body of ore.

4. In an apparatus of the character described, the combination of an endless perforated ore conveyer, electric heating means comprising; resistance conductors located ,over 'a ortion of the path of travel of the ore, an meafis for producing a draft downward over said resistance conductors and through said conveyer and the ore thereon.

5. In an apparatus of the character described, the combination of a perforated traveling o-re support, suction producing means at one side of the path of travel thereof, and an electric heater opposed thereto in such manner as to heat the draft created through the ore support and ore.

' cated in the last-mentioned means.

In an apparatus of the-character described, the combination with an ore conveyer, of an air chamber at one side thereof,

electric resistance heating elements-in said chamber, and means for causing a blast to pass from said chamber intothe interior of the ore body carried by the conveyer.

'8. In an apparatus of the character described, the combination with a perforated ore conveyer, of an air chamber at one side thereof formed of perforated blocks, electric resistance heating elements containing carbonaceous material mounted in .said blocks and crossing said chamber, and means for creating a draft from said chamber through the ore carried by the conveyer.

9. In an apparatus of the character described, the combination of an ore conveyer, and means for causing differentv blasts to pass through the ore carried thereby in such 'relationthat the ore encounters said blasts in succession.

' 10. In an apparatus of the character. described, the combination of an ore conveyer, means for causing air or the into the interior of the ore body or bodies carried by said conveyer, means for dividing the air flowing from the ore into successive portions relative to the travel of the ore, and electric resistance heating means for heating one portion of the air before passing through the ore. h 1

11. In an apparatus of the character described, the combination with an ore conveyer, of means for causing air or the like to pass through the ore carried thereby, successive stationary boxes avg-ranged to receive the gaseous products after passing through the ore, and electric resistance heating means at the other side of the conveyer oplike to pass posite one of said boxes to heat the air'before passing through the ore.

12. In an apparatus of the character described, the combination with an ore conveyer, of means for causing air or the like to pass through the ore carried thereby, successive stationary boxes arranged to receive the gaseous products after passing through the ore, and electric resistance heating means for preheating the air or the like that passes through the ore and into the first box.

13. In an apparatus of the character described, the combination of an ore conveyer, successive stationary air boxes at one side thereof, electric resistance heating elements at the other side of the conveyer opposite one of the boxes but not opposite a box farthe r along in the travel of the ore, and means for causing air or the like to pass through the ore into said boxes, one portion of the blast being preheated by said heating elements. a

14. In an apparatus of the character described, the combination of an ore conveyer., means for subjecting the ore carried thereby to a heated blast and thereafter to a cooling blast, and electric resistance elements for heating said heated blast.

15. In an apparatus of the character described, the combination of an ore conveyer, means for causing a blast to pass through the ore carried thereby at one portion of its travel, and means for preheating said blast, comprising perforated blocks through which the blast is conducted and electric resistance heating elements in said blocks.

16. A process of roasting or calcining ore,

which comprises moving the ore across an electrically heated blast of air. 17. A process of roasting or calcining ore, which comprises causing the ore to travel from a position of feeding to a position of discharge, and while it is in motion causlng an electrically heated blast of air to pass through it transversely of the direction of movement.

18. A process of roasting or calcining ore, which comprises transporting the ore, and while in motionfiring it by means of an electrically heated blast and thereafter cooling the fired product by a cool. blast.

In testimony whereof, I have signed my name to this specification, in the presence of.

1 two subscribing witnesses.

WILLIAM H. HAMPTON.

Witnesses FREDERICK KUNz, LOUELLA F. LITTLE. 

